The agency said that in some cases, Chemi Pharmaceutical did not test drug ingredients and other chemicals. Health Canada alleges that bogus results were provided to companies that had contracted the company's services.

Health Canada said Tuesday it is asking companies that sent drug ingredients and other chemicals for quality testing to the Mississauga, Ont., lab to halt sales of affected finished products until their safety can be confirmed.

The agency said there is no evidence that the health of Canadians has been compromised. Chemi Pharmaceutical did not immediately respond to request for comment.

"The company was involved in a wide range of testing of products," said Paul Glover, assistant deputy minister of the Health Products and Food Branch.

"So we have everything from veterinary drugs, to some natural health products to potentially some products used in foods to cosmetics to over-the-counter medicines to prescription products," Glover said in a media teleconference from Ottawa.

He said Health Canada has so far uncovered 53 products that need to be retested, and another 25 may need to be retested.

Only a portion of Chemi Pharmaceutical's work involved final testing of products before they were released on the Canadian market, said Glover.

Health Canada says it has contacted the RCMP to investigate the company, which had its licence suspended Monday. It said the suspension came after inspectors made a surprise visit to the lab following a phone tip alleging that Chemi was falsifying records.

The monetary value of the services involved is not yet known.

A list of products that require further testing is available at Health Canada's website.